How to Write an Invoice (Australian Guide, 2026)

Last updated 26 May 2026 · By InvoiceSonic Team · 7 minute read

Quick answer

To write an invoice in Australia: start with your business name, ABN, and contact details. Add the buyer's name (and ABN if the sale is over $1,000), a unique invoice number, the date, line items with quantity and price, subtotal, GST (if you're registered), and the total. State payment terms explicitly — "Due 14 days from issue date" — and send as a PDF by email within 24 hours.

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6 building blocks of a well-written invoice

These are the parts you actually have to write. The structural fields (numbers, dates) are mechanical — the wording of these six blocks is what separates a professional invoice from one that gets ignored.

  1. 1

    Write your business header clearly

    Lead with your legal business name in bold, your ABN underneath, then your trading address and contact details. If you trade under a different name to your registered name, write "[Trading Name] trading as [Legal Name]" — required by Australian Consumer Law.

  2. 2

    Address the buyer formally

    Use "Bill To:" followed by their full legal business name (not "Hi John"). For invoices over $1,000 include their ABN. Even for small clients, treat the document as if a stranger will read it years later in an ATO audit.

  3. 3

    Title the document correctly

    Say "Tax Invoice" only if you are GST-registered and the sale is $82.50+. Otherwise use "Invoice" — never "Receipt" (different document) or "Bill" (informal). The title sits in the largest type on the page.

  4. 4

    Write line items with specifics

    Replace "Services rendered" with "Plumbing labour — 4 hours @ $120/hr". The ATO can reject vague descriptions in an audit, and specific items reduce buyer pushback. Quantity, unit, rate, total — all four columns matter.

  5. 5

    State payment terms explicitly

    Write "Payment due 14 days from invoice date" — not "ASAP" or "soon as possible". Stating terms creates contractual certainty. Add the late-payment clause: "1.5% interest per month on overdue balances" is the Australian small-business standard.

  6. 6

    Write a professional cover email

    Subject line: "Invoice INV-0042 from [Your Business] — due 14 days". Body: 3 short sentences acknowledging the work, noting the attached PDF, restating the due date and payment method. Attach the invoice as a PDF — never a Word document.

How to phrase line items

The single biggest difference between an amateur invoice and a professional one is the specificity of line items. Compare:

✕ AMATEUR
Services .................... $1,500
✓ PROFESSIONAL
Plumbing labour, 8 hrs @ $120/hr ........... $960
Materials — copper piping, fittings .... $340
Site disposal fee ............................. $200

Four formulas that always work:

  • Hourly work: "[Task] — [N] hours @ $[rate]/hr"
  • Fixed-scope project: "[Deliverable] — [scope details]"
  • Materials: "[Item type] — [specifics, e.g. brand, qty]"
  • Recurring: "[Service] — [period covered]"

How to phrase payment terms

Payment terms have to be explicit and enforceable. "ASAP" and "on receipt" are weak in court. Use this language:

Payment terms: Net 14
Due date: 9 June 2026
Late fee: 1.5% per month on overdue balances
Payment methods: Bank transfer, BPAY, or Stripe

"Net 14" is shorthand for "due 14 days from invoice date" — every business in Australia understands it. For sole traders and freelancers, Net 7 is increasingly common (and recommended for cash flow). For corporate clients, Net 30 is normal.

How to write "trading as" on an invoice

Under Australian Consumer Law, if you trade under a name that isn't your registered legal name, you must show both names on the invoice.

SOLE TRADER WITH BUSINESS NAME
John Smith trading as Smith Plumbing
COMPANY WITH TRADING NAME
Smith Holdings Pty Ltd trading as Smith Plumbing
SOLE TRADER USING OWN NAME
John Smith (no "trading as" needed)

If you registered a business name with ASIC, the registered name goes in the trading-as position. Your ABN sits on the line below either way.

How to write the invoice email

Most invoices get sent by email. The cover email matters — it sets the tone, restates the terms, and bumps payment speed.

Subject: Invoice INV-0042 from Smith Plumbing — due 9 June

Hi Sarah,
Thanks for the work on the Marrickville bathroom — pleasure as always.
Please find the invoice (INV-0042) attached as a PDF. Total is $1,430.00 (GST inclusive), due Tuesday 9 June.
Bank details are on the invoice — happy to take BPAY, Stripe, or direct transfer. Let me know if you have any questions.
Cheers,
John
Smith Plumbing | ABN 12 345 678 901

Three things this email does well: the subject line includes the due date (it doesn't get buried), the body restates the amount and date (in case the PDF doesn't open), and the bank details note acknowledges multiple payment paths.

Industry-specific examples

Building / construction

Detail labour and materials separately. Include progress-payment milestones for jobs over $5K. Show your builder's licence number if your state requires it.

→ Construction invoice template

Painting

Quote by room or by surface area. List preparation work separately from coats. Materials line should specify brand/quality if it was discussed in the quote.

→ Painting invoice template

Freelance / contractor

Either hourly with explicit hours, or fixed-scope with a one-line deliverable description. State your ABN prominently — no ABN means 47% PAYG withholding.

→ Freelance invoice template

Sole trader (one-off services)

Use Net 7 terms — short cash cycles matter. Use your name (or "trading as" if you registered a business name). Show "No GST has been charged" if under the $75K threshold.

→ Sole trader invoice template

Common writing mistakes

  • Vague descriptions like "Services rendered" or "Work as quoted" — the ATO can reject these in an audit
  • Informal greetings ("Hi mate") in the cover email — it reads as unprofessional and undermines the document
  • "Payment due on receipt" or "ASAP" — both are unenforceable; state a specific number of days
  • Missing "Tax Invoice" header when you're GST-registered — invalidates the invoice for GST credit purposes
  • No mention of trading-as relationship when one applies — breaches Australian Consumer Law
  • Combining multiple jobs into one invoice without dates — makes reconciliation and disputes harder

Frequently asked questions

What is the best way to write an invoice in Australia?

Start with your business name, ABN, and contact details at the top. Then add the buyer's details, a unique invoice number, the date, line items with quantity and price, the subtotal, GST (if registered), and total. State payment terms explicitly ("Due 14 days") and send the invoice as a PDF by email within 24 hours of completing the work.

How should I write line items on my invoice?

Be specific. Replace "Services" with the actual work and its quantity — "Plumbing labour, 4 hours @ $120/hr = $480" or "Logo design — 1 round of revisions". The ATO can reject vague descriptions in an audit, and specific line items prevent client disputes about what was billed.

How do I write "trading as" on an invoice?

Write your registered business name first, then "trading as" and your business or trading name. Example: "John Smith trading as Smith Plumbing". This is required under Australian Consumer Law any time you trade under a name that isn't your registered legal name (sole trader's own name, company name, or partnership name).

How do I write payment terms on an invoice?

State the exact due date or the timeframe explicitly: "Payment due within 14 days of invoice date" or "Due by 15 June 2026". Avoid vague terms like "ASAP" or "on receipt". Add a late-fee clause if you want — "1.5% interest per month on amounts overdue" is the Australian small-business norm.

How do I write an invoice email to a client?

Subject line: "Invoice [number] from [your business] — due [date]". Body: keep it to 3-4 sentences. Acknowledge the work briefly, note the attached PDF, restate the due date and payment method, and offer to answer questions. Always attach the invoice as a PDF, never as a Word doc or in the email body itself.

How do I write a tax invoice (with GST)?

Title the document "Tax Invoice", include your ABN, the 8 ATO-required fields, and show GST as a separate line. Example: Subtotal $1,000, GST (10%) $100, Total payable $1,100. See our tax invoice guide for the full ATO field list.

How do I write an invoice as a sole trader?

Use your registered name or "[Your Name] trading as [Business Name]", include your ABN, and follow the same structure as a business invoice. If you are GST-registered (turnover over $75K), write it as a tax invoice. See our sole trader invoicing guide for the specifics.

How do I write an invoice for building or construction work?

For building work, line items should detail each stage: labour hours, materials (often as a separate subtotal), site costs, and any subcontracted work. Include progress-payment terms if it's a larger job ("30% deposit, 40% mid-project, 30% on completion"). Add your builder's licence number if your state requires it on invoices.

How do I write a deposit or progress invoice?

Title it "Deposit Invoice" or "Progress Invoice" (whichever applies), explain the milestone ("30% deposit for kitchen renovation"), and clearly state that final invoice will follow on completion. If GST-registered, show GST on the deposit amount — not the full project value.

How long should the descriptions on my invoice be?

Aim for one descriptive line per item — long enough to be unambiguous, short enough to fit a typical invoice layout. "Web design — homepage and 4 inner pages" beats both "Services" (too vague) and a paragraph-long description (too much for the format).

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